Process for making detergent composition



June 2, 1959 H. TECKLENBURG PROCESS FOR MAKING DETERGENT COMPOSITION Filed April 23, 1956 IN V EN TOR. firm X 75-00. t/VBURG,

' ATTQRNEYS.

United States Patent PROCESS FOR MAKING DETERGENT COMPOSITION Harry Tecklenburg, Springfield Township, Hamilton County, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Application April 23, 1956, Serial No. 579,904

6 Claims. (Cl. 252-89) In a co-pending application in the name of Benjamin R. Britt entitled Detergent Composition, Serial No. 579,744, filed April 23, 1956, a granular detergent product is taught having a novel and distinctive appearance. This appearance is attained by admixing a relatively small proportion, say 2% to 30% of highly colored granules with a bulk of other granules which are uncolored or are relatively lightly colored in a contrasting hue. The result is a product having a distinctive speckled or flecked appearance capable of wide variation through color selection, but serving well to distinguish the Britt detergents from goods of different origin or goods having different specific performance or both.

It is taught in the said co-pending application that the colored granules employed to give the distinctive appearance must be strongly or vividly colored, i.e., must have a chroma in accordance with the Munsell system of more than 4 and a Munsell value of about 4 to 7, although the hue may be chosen as desired.

The colored granules should also be of sufiicient size to provide the distinctive speckled appearance. A suitable screen analysis for granules was found to be:

Less than about 1% retained on a screen of 14 meshes to the inch.

About 40% on 48 meshes per inch.

Less than about through 65 meshes per inch.

The bulk of the distinctively colored granules should have minimum dimensions of more than about 0.2 millimeter and should be retained on a screen of 35 meshes to the inch.

The over-all coloring of soap or synthetic detergent granules is not new per se, but has been practiced in the previous art by adding the coloring material, in solution or suspension in water to the crutcher or mixer containing the soap or detergent before spray drying. The spray dried product was thus all of one color. While it is possible to produce the distinctive speckled appearance of the product of the co-pending application by adding coloring material to the soap or detergent in a crutcher or mixer, then spray drying to produce colored granules followed by mixing these granules with uncolored or differently colored granules otherwise produced, such a procedure is both difiicult and costly. It either involves the provision of diiferent equipment for the manufacture of the several types of granules or it involves expensive cleaning operations if the same apparatus is to be used successively for different types of granules. Such cleaning operations are not always satisfactorily thorough and frequently a succeeding batch of soap or detergent has its color affected by the color of a preceding batch.

Another disadvantage of separately making granules of different characteristics lies in the added cost of mixing them, which requires separate equipment. Moreover, where granules are separately made in diiferent batches, inadvertent differences in size, density and the like may be encountered.

An important object of the present invention has to do with the overcoming of the foregoing difiiculties.

It is an object of this invention to provide a simple, inexpensive and thoroughly satisfactory means and method for the continuous production of the granular products of the said copending application.

These and other objects of the invention, which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, are accomplished by that procedure and in the use of those devices of which an exemplary embodiment will hereinafter be described. Reference is made to the accompanying drawing which shows in diagrammatic fashion the essentials of the apparatus of this invention.

It has been discovered that a distinctive speckled product of good contrast and physically stable nature may be produced inexpensively by continuously diverting a portion of a stream of granular product, coloring the diverted portion and returning it to the stream of uncolored product so as to be blended therewith. The coloring of the granules of the diverted stream is preferably done by spraying, and for this purpose water solutions of dyestuffs are preferably used. It is significant that in the present process and apparatus the color-treated granules are not reexposed to the heat of spray drying so that the dyestuffs or other coloring material do not have to be heat fast.

As set forth in the said co-pending application, coloring materials should be stable to alkali, non-toxic, nonirritating and non-substantive to fabrics. Reference is made to the said co-pending application for a disclosure of dye pigments and coloring materials which maybe used thus forming no limitation on what is herein claimed. For convenience herein, the sprays of all coloring materials will be referred to as solutions of the dyestuffs, it being understood that the expression is intended to embrace colloidal and other dispersions and suspensions thereof.

Further, in the practice of the invention, the diverted stream which has been treated by spraying is caused to rejoin the main stream of the detergent granules, which is conveyed, usually from a spray drying tower or from storage, in such fashion as to cause a drying of the colorsprayed material as well as its uniform distribution throughout the body of the granules.

Referring now to the drawing, a granular product is shown as delivered to a vertical air lift conduit 3, by means of a belt conveyor 1. The granular product may be produced in any commercial fashion, but in most instances will be a spray-dried product. The belt conveyor 1 may deliver the granular product directly from a spray tower or from storage.

Within the air lift conduit 3, there will be maintained a stream of air of sufiicient velocity to carry the product upwardly, with the exception that any substantially heavier impurities or exceptionally large lumps of granules will fall by gravity through a bell-shaped opening at the lower end of the air lift and be caught in a buggy 2 by means of which they may be returned to the crutcher if desired.

At the top of the air lift there is a gravity separator 4 which removes all of the product from the air stream excepting the extreme fines. These pass out a stack or conduit 5 to filters or other separating means. The fines so separated may also be returned to the crutcher feeding the spray tower.

The product removed by the gravity separator 4 passes through a conduit 6 or otherwise is conveyed to a vibrating screen 7, the primary function of which is to remove granules too large to dissolve readily when the product is used. The granules going through the screen will be of acceptable size; and in a carefully controlled procedure will normall have a screen analysis quite similar to that set forth above. The over-size material separated by the screen 7 is cause in a hopper 9 and transferred by conduit 13 to a buggy 14 to be returned to the crutcher.

The product passing through the screen 7 is caught by a hopper 8 and delivered to a conduit 10. Conduit 10 has two branches as shown. One marked 10:: delivers the product to a product belt 12 for carrying it to packaging devices or the like. The other branch, 10b, may be used for delivering the product to storage buggies 11 as may be desired. A valve 15 controls the flow of the product from the conduit 10 to either of its branches.

A diverter conduit 16 is connected to the conduit 10 in such fashion as to divert continuously a certain percentage of the granules flowing through the conduit 10. The percentage so diverted may be treated as hereinafter set forth. The conduit 16 continuously delivers the diverted granules to holder 16a feeding a variable speed belt which in turn delivers the granules to a rotating drum 18 in which the granules are to be sprayed for coloration.

A source 19 of sprayable coloring material such for example as a dye solution, and provided with a pump 20, is connected by means of a conduit 21 to a series of spray heads 22 within a rotating drum 18.

The coloring action occurring in the drum 18 is not necessarily thorough in the sense that all of the granules passing through the drum will be equally colored or colored with the same intensity. While it is possible to secure complete coloration of all of the granules by the use of a relatively large quantity of the coloring solution, such an operation is not preferred because it results in the treatment of the granules with a relatively large proportion of the water vehicle of the dying solution. This complicates the drying problem. It is ordinarily preferred to so conduct the spraying treatment that a minimum quantity of vehicle is used although this may result in coloring less than the full number of granules passing through the drum 18. Coloring of individual granules is not improved by the use of an excess of the dye. Where less than all of the granules are colored in the drum 18, compensation may be made by diverting, as at 16. a larger percentage of the total output of granules. For example, if 10% of the granules is diverted through the conduit 16, and half of these granules are colored strongly in the drum 18, the result will be the addition of about of vividly colored granules to the main stream of the product.

Colored granules are delivered from the drum 18 to the hopper of a conduit 23 by means of which they return to the air lift 3. If the percentage of fines has been increased by the handling due to coloration, these fines will be removed by the gravity separator 4. The turbulence in the air lift 3 will result in an essential mixing of the colored granules with the non-colored granules. Further, the gases in the air lift will result in a suflicient drying of the colored granules so that the moisture content of the completed product will be substantially unaffected.

It will be observed that a small fraction of the granules will pass through the spray drum more than once. If the diverting means 16 withdraws of the granules from the stream, on the second time around, 10% of these granules will be diverted through the spray drum. Thus, 1% of the colored granules will be exposed to the coloring spray twice. It has not been observed that this produces any difference in the appearance of the colored granules or in the appearance of the completed product.

The following example discloses one way in which the invention can be practiced.

Example 1 Using the arrangements shown in the drawing, the diverter 16 was set so as to divert 10% of the granules passing through the conduit 10. An 0.8% water solution of Erioglaucine was placed in the color solution tank 19, and the speed of the pump 20 together with the speed .4 of the variable delivery belt 17 were so regulated that there was sprayed on the granules going through the drum 22 an amount of the dye solution equal to 4% of the weight of the granules. The granules were discharged into the main stream going through the air lift 3, by means of the conveyor 23. The product at the discharge end of the product belt had a distinctive blue speckled appearance and was found to be permanent and not subject to segregation or modification of the general appearance after handling and storage.

If it is desired to remove an additional percentage of fines from the granules being colored in the drum 18, this may be accomplished by incorporating a screen in the coloring line ahead of the drum. The use of a screen of 35 meshes to the inch at this point will serve to remove substantially all materials of such fineness that they do not contribute usefully to the speckled appearance of the product.

The use of the apparatus is not confined to the manufacture of a product in which a minor percentage of highly colored granules is mixed with a larger bulk of uncolored granules. The bulk of the granules may itself be colored as by crutcher coloring in known ways. A distinctive speckled appearance will still be obtained with a small percentage of highly colored granules provided the coloration of the bulk of the granules is of a contrasting hue and preferably of a light or pastel shade.

In instances where it is desired to produce a product characterized by a relatively small percentage of multicolored granules in a larger bulk of lightly colored or non-colored granules, it is possible to provide one or more additional coloring lines, each having means for diverting a portion of the main stream passing through conduit 10 and each delivering its product to the lower end of the air lift 3 for purposes hereinabove set forth. Thus, by way of example, a highly attractive multicolored product may be made by mixing granules colored blue and granules colored red with a bulk of uncolored or lightly colored granules.

In the event that a product is being made in which granules of soap or detergent are mechanically mixed with finely divided builders, such for example as phosphates, it is preferred to manufacture the soap or detergent granules, divert and color a portion thereof, and mix the colored granules with the uncolored granules, all prior to admixture of the product with the pulverulent builders.

The treatment of the granules in the drum 18 is not limited to a treatment with coloring substances. Other treatment substances may be used in addition, including, but without limitation, anti-caking agents, sudsing control agents and substantive fluorescent dyes which control the apparent whiteness of fabrics washed with the composition. When such modifications are practiced, the highly colored granules or particles become an active component of the composition; and the process and apparatus furnish a convenient way of controlling and varying the percentage of important minor-quantity ingredients in the composition.

Modifications may be made in the invention without departing from the spirit thereof. The invention having been described in an exemplary embodiment, what is claimed as new and desired to be secured by Letters Patent is:

l. A process of continuously making a speckled granular detergent composition which comprises the steps of (l) subjecting detergent granules to an air lift to form a continuously flowing stream, (2) separating fines from the continuously flowing stream, (3) continuously screening the resulting granules, (4) continuously diverting a fraction of the screened granules controlled as to quantity, (5) spray-treating the diverted fraction with a water solution of coloring material, and (6) introducing the so-treated granules in said air lift and combining same with fresh untreated granules passing through said air lift at a point sutficiently ahead of the separation of fines whereby spray-treated granules are dried and mixed thoroughly with said fresh untreated granules, the quantity of the so-treated granules discharged with the undiverted fraction of step (4) being approximately 2% to 30% of the total quantity of the mixture.

2. The process of claim 1 in which more than one fraction of said granules is diverted and difierently colored before said fractions are recombined, to produce a multi-colored product.

3. The process of claim 1 in which the granules of the main flowing stream have color added prior to step (1).

4. The process of claim 1 in which the diverted and sprayed fraction is mixed with the unsprayed fraction in the lower part of said air lift, at least two-thirds of said air lift being traversed by the sprayed granules, whereby to dry the sprayed granules.

5. The process of claim 1 in which the coloring material is capable of imparting to the granules a color of selected hue high in chroma and low in value in accordance with the Munsell system of color notation.

6. The process of claim 2 in which the main stream of granules, after fractions thereof have been diverted, is itself colored differently from the coloring of the diverted fractions.

References Cited in the file of this patent UNITED STATES PATENTS 1,779,517 Stevenson et al Oct. 28, 1930 1,818,367 Wallace Aug. 11, 1931 2,502,881 Parker Apr. 4, 1950 2,540,348 Reed Feb. 6, 1951 2,567,207 Hoge Sept. 11, 1951 2,623,856 Sanders Dec. 30, 1952 2,657,797 Ledgett et a1 Nov. 3, 1953 2,666,731 Bergstrom Ian. 19, 1954 2,674,497 Thayer Apr. 6, 1954 2,712,476 Happel July 5, 1955 2,715,110 Packard Aug. 9, 1955 2,738,332 Compa Mar. 13, 1956 2,767,146 Bonewitz et a1 Oct. 16, 1956 OTHER REFERENCES Modern Soap Making, by Thomssen and Kemp, pp. 251, 265, MacNair-Dorland Co., New York (1937).

Soaps and Detergents, by Thomssen and McCutcheon, pp. 299-305, 211, 213, 214, MacNair-Dorland Co., New York (1949). 

1. A PROCESS OF CONTINUOUSLY MAKING A SPECKLED GRANULAR DETERGENT COMPOSITION WHICH COMPRISES THE STEPS OF (1) SUBJECTING DETERGENT GRANULES TO AN AIR LIFT TO FORM A CONTINUOUSLY FLOWING STREAM, (2) SEPARATING FINES FROM THE CONTINUOUSLY FLOWING STREAM, (3) CONTINUOUSLY SCREENING THE RESULTING GRANULES, (4) CONTINUOUSLY DIVERTING A FRACTION OF THE SCREENED GRANULES CONTROLLED AS TO QUANTITY, (5) SPRAY-TREATING THE DIVERTED FRACTION WITH A WATER SOLUTION OF COLORING MATERIAL, AND (6) INTRODUCING THE SO-TREATED GRANULES IN SAID AIR LIFT AND COMBINING SAME WITH FRESH UNTREATED GRANULES PASSING THROUGH SAID AIR LIFT AT A POINT SUFFICIENTLY AHEAD OF THE SEPARATION OF FINES WHEREBY SPRAY-TREATED GRANULES ARE DRIED AND MIXED THOROUGHLY WITH SAID FRESH UNTREATED GRANULES, THE QUANTITY OF THE SO-TREATED GRANULES DISCHARGED WITH THE UN DIVERTED FRACTION OF STEP (4) BEING APPROXIMATELY 2% TO 30% OF TIME TOTAL QUANTITY OF THE MIXTURE. 